GiveWell's cost to save a life has gone from $4,500 to a range between $3,000 and $5,500:
https://www.givewell.org/how-much-does-it-cost-to-save-a-life
From at least as early as December 2023 (possibly as early as December 2021 when the page says it was first published) until February 2024, that page highlighted a $7.2 million 2020 grant to the Against Malaria Foundation at an estimated cost per life saved of $4,500.
The page now highlights a $6.4 million 2023 grant to the Malaria Consortium at an estimated cost per life saved of $3,000.
You can see all the estimated cost per life saved (or other relevant outcome) for all GiveWell's grants at this spreadsheet, linked-to from:
USAID took down its archive of evaluation reports, but a high school student happened to have downloaded them for a ML project, and they are now available online again:
https://www.aiddata.org/blog/before-reimagining-development-data-remember-what-weve-learned
Mad story!